Pairing communication devices is a technology wherein two devices establish a communication link amongst themselves. Bluetooth, which represents one of such technologies, is a wireless protocol which exchanges data over short distances. Bluetooth helps simultaneously connect up to eight devices. Operating at a frequency of about 2.45 gigahertz, Bluetooth works with weak signals of 1 milli-watt as compared to 3 watts for cellphone communication. This is largely responsible for limiting the range for Bluetooth communication to 10 meters (32 feet). Bluetooth uses a technique called spread spectrum frequency hopping that makes it rare for more than one device to be transmitting on the same frequency at the same time. A typical Bluetooth communication protocol follows the following procedure. Multiple devices, which are connected, are kept within the specified range, the process referred to as ‘Discovering’. A source device which wishes to establish a connection with a target device, generates an authentication code also known as the ‘Passkey’. The source device sends the passkey to the target device, which a user of the target device then enters when prompted. Once the passkey is entered and authenticated, the devices are linked and are ready to exchange data.
Bluetooth based systems create a personal area network (PAN), or piconet, that may fill a room or may encompass no more distance than that between a device such as a mobile phone on a belt-clip of a user and a headset worn over the head of the user. Once a piconet is established, the devices randomly hop frequencies in unison so they stay in touch with one another and avoid other piconet networks that might be operating close by.
However, there are many drawbacks associated with the Bluetooth communication technology and protocol. A major drawback is that of device discovery. Since Bluetooth based data transfer is distance specific, problems with regards to the devices not being identified in a discoverable area are quite common Another problem is that of the passkey. Bluetooth protocol requires that both the sender and the receiver of the passkey be able to accurately generate and replicate the passkey on both the source and target devices. This is a highly challenging task and often leads to errors. Often, despite being connected, the devices are not able to transfer data. This problem is attributed to the low signal strength.
There have been several endeavors to solve some of these problems. For example, WO2008001064 attempts to solve the problem related to passkey generation, transfer and inputting. The solution involves introducing the Bluetooth address details to contacts database of a device. When a connection needs to be established, the address is retrieved from the contacts database and immediately followed by sending communication data packets. While the solution does take care of the some of the problems associated with connecting via passkeys, the problems with short range, connection problems and low power data transfers still persist.
Reference article ‘Scott, D., Sharp, R., Madhavapeddy, A.,and Upton, E. 2005. Using visual tags to bypass bluetooth device discovery, Mobile Computing and Communications Review, 1,2,1-12.’, attempts to solve the problem associated with the passkeys generation, transfer and inputting. The solution involves use of camera phones to capture visual tags which decode to transfer the Bluetooth address of the target device(s). While this point and shoot approach eliminates the need to generate passkeys, the problems with regards to short range, connection problems and low power data transfers still persist.
Hence there is felt a need for a protocol and technology which will address the aforementioned problems and enable secure and efficient wireless communication.